THE Joba Rules are controversial. The Joba Rules are often confusing, even to the manager who must abide by them. The Joba Rules are too frequently treated like war plans by GM Brian Cashman rather than what they are – guidelines for how to use a reliever.

But here is the most important item about the Joba Rules: They have worked.

Chamberlain has pitched well and stayed healthy. And because he has done that over a period of time, the young righty has had his restrictions loosened to the point where he should be available just about every game in a playoff schedule heavy in off-days.

Were there several times since his Aug. 7 promotion in which Chamberlain could have made a difference by being available? Sure. But that criticism is negated by the way events have played out. The Yanks have essentially had the baseball version of having their cake and eating it, too.

They have gone 14-2 in the games in which Chamberlain has pitched and, despite his absence from certain winnable games, the Yanks are going to the playoffs anyway. So his forced unavailability has not cost the Yanks October, and his health has not been jeopardized.

It could be argued the Yankees needlessly babied Chamberlain, that there is no way to definitively know he could not handle a heavier workload. That is true. But the Yanks were armed with reams of data that showed a too-frequent injury correlation when young starters were asked to quickly transition to stressful bullpen roles. And the Yankees front office was simply unwilling to risk the next decade of a potential Roger Clemens clone or their version of Justin Verlander, no matter the demands to win in 2007.

As even Doug Mientkiewicz says of the phenom, “What keeps getting lost here is that he has never been a reliever. Among the guys, we keep saying, ‘Can you imagine facing that stuff for seven or eight innings?'”

Cashman was unwilling to jeopardize seeing that in 2008. So for 2007, he let everyone involved in the process know if Chamberlain did not take to the relief role in results or physically, then the experiment would be abandoned. But the GM also told the other executives if Chamberlain took to it well, he would have his role evolve. So it is in the Yankees’ best interest, therefore, to seal a playoff spot as quickly as possible.

That would allow them to some extent to treat this week a bit like spring training and assign outings to Chamberlain, which should bring him to his next and final hurdle: pitching on consecutive days. If he comes through that fine, Chamberlain should pretty much be available for every playoff game. The way the postseason is devised this year to appease TV, the only time the Yanks would face games on three consecutive days (barring a rainout) would be if they made it to Games 3-4-5 of the World Series.

So that should appease Yankees veterans who have been suspect about the limitations on Chamberlain. On Sunday, Mike Mussina vented that Chamberlain must be available for every postseason game. Yesterday Johnny Damon told the Post’s Mike Puma, “There are a lot of guys who play here to win a championship, and if using that kid gives us a better chance, we better do it.”

Cashman has grown grouchy of discussing the subject. He is tired of being second-guessed and furious that members of the organization are discussing how Chamberlain will be deployed, saying it gives the opposition too much insight. But Cashman should lighten up on this. In this town, he cannot restrain information for a player who arguably is already the most popular Yankee. There are more rules for Kyle Farnsworth than Chamberlain and no one cares much because, well, he is Kyle Farnsworth.

Besides, has knowing when Chamberlain is available actually helped opponents? His 0.42 ERA and .135 batting average against proclaim that Joba has ruled regardless of preparation for him.

So Cashman should not be small-minded, but rather bask in being right about the big picture. He ordered up the Joba Rules, and with Chamberlain healthy, effective and seemingly ready for any postseason role, the plan has worked brilliantly.